1. Field of the Invention
The present invention relates to a printing apparatus, control method thereof, and storage medium.
2. Description of the Related Art
There has conventionally been known a digital copying machine having an electronic sorting function of temporarily storing, in a memory such as a hard disk, image data obtained by reading the image of an original, repetitively reading out image data of an arbitrary original from the memory, and copying and printing it. With this function, the digital copying machine can discharge copy sheets while sorting them, even without a sorter having a plurality of bins.
In PDL (Page Description Language) printing, a digital copying machine receives PDL data of an application in a host computer via a network. With the electronic sorting function, the digital copying machine rasterizes the received PDL data into a bitmap image, temporarily stores it in a memory such as a hard disk, repetitively reads out an arbitrary image from the memory, and prints it while sorting sheets.
A printing apparatus prepares face-down output for discharging output sheets with their printed surfaces facing down, and face-up output for discharging output sheets with their printed surfaces facing up. In face-down output, image data of an original are printed in the normal order. In face-up output, since image data of an original are printed in the reverse order, all image data of the original are temporarily stored in a memory and then printed in the reverse order.
Depending on the page count of an original such as Nin1 reduction layout, a final sheet in normal order output may have a special layout. For example, when printing seven pages of an original in a 4in1 reduction layout, “1, 2, 3, 4” pages are printed on the first sheet, and “5, 6, 7” pages are printed on the second sheet. If these pages are printed simply in the reverse order, “4, 5, 6, 7” pages are printed first and then “1, 2, 3” pages are printed, and the layout result differs from that in normal order output. To prevent this, Japanese Patent Laid-Open No. 2007-203578 proposes a method of, in reverse order output, calculating the layout of the first sheet in reverse order output in accordance with the page count of an original and the reduction layout setting.
In double-sided printing, when the page count of an original is an odd number, the reverse of the final sheet becomes blank. For example, double-sided printing of three pages of an original results in “obverse 1, reverse 2” and “obverse 3, reverse blank”. Printing this original in reverse order results in “obverse 3, reverse 2” and “obverse 1, reverse blank”. Even in this case, imposition in normal order output and the printing result by reverse order output differ from each other. Hence, similar to the reduction layout, imposition on the first sheet in reverse order output is calculated from the page count of an original and the double-sided printing setting. When the page count of an original is an odd number, the obverse surface of the first sheet in reverse order output is set to be blank, and when it is an even number, the obverse surface of the first sheet in reverse order output is printed. That is, a conventional printing apparatus performs imposition and layout for the first sheet in reverse order output by calculation in accordance with the page count of an accumulated original and the set values of a job.
In double-sided printing of originals of different sizes, imposition cannot be performed on the obverse and reverse of a single output sheet. More specifically, if an A4-size original and A3-size original are imposed on the two surfaces of one A4-size sheet, the image of the A3-size original extends outside the sheet and cannot be normally printed. To prevent this, when performing double-sided printing of, for example, A4- and A3-size originals, the A4-size original is printed on the obverse of an A4-size sheet while leaving its reverse surface blank. Also, the A3-size original is printed on the obverse of an A3-size sheet while leaving its reverse surface blank. In this fashion, to perform double-sided printing of originals of different sizes, when the original size changes, the paper size is changed. If there is no original corresponding to the reverse surface, the reverse surface remains blank. In this case, if imposition and layout for the first sheet are executed by calculation based on the page count of an accumulated original and the set values of a job according to the method disclosed in Japanese Patent Laid-Open No. 2007-203578, an output result in reverse order output differs from one in normal order output.